style: align light palette to Quiet Luxury reference

- Page background now #F8F9FA (was white); tokens matched to reference:
  foreground slate-900, muted slate-50/slate-500, border slate-200,
  card pure white, tertiary slate-400, border-light slate-100
- Sidebar colors matched to mock: emerald-200/70 inactive, white/8 active
  with emerald-400 active icon, emerald-50 logo, red-300 logout, right border
- Content wrapped in max-w-[1400px] centered container (px-8 lg:px-10)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/globals.css

@@ -16,9 +16,9 @@
    them to Tailwind color utilities (bg-background, text-primary…).
    ========================================================= */
 :root {
-  /* Base */
-  --background: #ffffff;
-  --foreground: #1a1a1a;
+  /* Base — sfondo generale app #F8F9FA (color-bg-light), testo slate-900 */
+  --background: #F8F9FA;
+  --foreground: #0F172A;
 
   /* Brand primary — verde scuro iamcavalli */
   --primary: #1A463C;
@@ -28,29 +28,29 @@
   --accent: #DEF168;
   --accent-foreground: #1A463C;
 
-  /* Secondary — grigio neutro */
-  --secondary: #f4f4f5;
-  --secondary-foreground: #1a1a1a;
+  /* Secondary — grigio neutro (slate-100) */
+  --secondary: #f1f5f9;
+  --secondary-foreground: #0F172A;
 
-  /* Muted — per testi e sfondi secondari */
-  --muted: #f9f9f9;
-  --muted-foreground: #71717a;
+  /* Muted — sfondi secondari (slate-50) / testo slate-500 */
+  --muted: #f8fafc;
+  --muted-foreground: #64748B;
 
   /* Destructive */
   --destructive: #ef4444;
   --destructive-foreground: #ffffff;
 
-  /* Card */
-  --card: #ffffff;
-  --card-foreground: #1a1a1a;
+  /* Card — bianco puro (color-bg-card) */
+  --card: #FFFFFF;
+  --card-foreground: #0F172A;
 
   /* Popover */
-  --popover: #ffffff;
-  --popover-foreground: #1a1a1a;
+  --popover: #FFFFFF;
+  --popover-foreground: #0F172A;
 
-  /* Border / Input / Ring */
-  --border: #e5e7eb;
-  --input: #e5e7eb;
+  /* Border (slate-200 = border-card) / Input / Ring */
+  --border: #e2e8f0;
+  --input: #e2e8f0;
   --ring: #1A463C;
 
   /* Semantic — stato task/pagamenti */
@@ -58,10 +58,10 @@
   --warning: #ca8a04;
   --info: #2563eb;
 
-  /* Legacy — usati inline nei componenti esistenti */
-  --tertiary: #999999;
-  --bg-subtle: #f9f9f9;
-  --border-light: #e5e5e5;
+  /* Legacy — text-light slate-400, border-soft slate-100 */
+  --tertiary: #94A3B8;
+  --bg-subtle: #f8fafc;
+  --border-light: #f1f5f9;
 
   --radius: 0.5rem;
 }